3o6 



SCIENCE. 



[Vol. X. No. 255 



mind that plays so prominent a role in the science of this century. 

 Beginning his career as a physiologist, he soon saw in the pursuit 

 of his specialty the opportunity of bridging over the gap between 

 body and mind, or, better, of restoring to its original unity the 

 study of the two as different aspects of one phenomenon. The 

 field of physiological psychology had been simply touched upon 

 liere and there. It lacked systematic treatment as well as recogni- 

 tion as a distinct science. Both of these he attempted to supply ; 

 -and the attempt, considering the inherent difficulty of the subject, 

 has been eminently successful. He published the first systematic 

 text-book in this field in 1874, a second and much enlarged edition 

 -appeared in 1880, and the third has just appeared. In these thir- 

 teen years the growth of the science has been rapid, and the fact 

 that the validity of this increase is in great part not yet tested 

 makes it necessary to record much that our successors will be able 

 to omit. But independently of this technical aspect of the study, 

 science owes a debt to this movement similar to that it owes to 

 Darwin. The one introduced the same rejuvenating ferment into 

 the discussion of philosophical problems as has the other into that 

 ■of biological problems. It has given meaning to facts formerly 

 •isolated and uninterpreted, has erected a sign-post directing the 

 way for the future, and has prevented much useless and irrelevant 

 speculation. It is to be hoped that the objects and methods of this 

 science are to-day too well known to need more than a mention in 

 this connection. 



The question of most natural interest in the notice of this text- 

 book is the extent and nature of the changes that have been made 

 in passing from the second to the third edition. While the author 

 has made alterations in all parts of the work, the topics that have 

 been most altered are the following, and they indicate very well the 

 fields in which recent research has been active. The anatomy 

 and physiology of the central nervous system, and particularly of 

 the parts connected with the highest psychic activities, have been 

 much revised. Next, the experimental study of sensation, both 

 •qualitatively and quantitatively, has received valuable additions 

 from many hands. The chapter on auditory perceptions has been 

 rewritten, and that describing the measurement of the times of psy- 

 ■chic processes has been made to include the most recent studies, 

 ■especially those made in Professor Wundt's own laboratory. 

 Whether these changes justify the publication of a new edition is a 

 •question upon which opinions will differ. A great deal of what has 

 been added has been already published in the Philosophise he 

 Studien, edited by Professor Wundt ; and, as most of this material 

 IS only of technical interest, its incorporation into a text-book is 

 hardly an advisable step. Again, the advance in the knowledge of 

 facts has brought with it an advance in the presentation of theoreti- 

 cal views, and Professor Wundt has hardly undertaken the radical 

 kind of revision that the appreciation of these would justify : in 

 other words, if a text-book in physics were written upon the plan of 

 this work, it would amount to a cyclopaedia, and the reader of that 

 cyclopsedia would be at a loss to distinguish the important and 

 ■clearly established from the unessential and provisional. The 

 'book has grown thicker where it should have grown deeper. 

 Finally, at the risk of singling out a trivial matter, an American 

 reader is very much struck with the absence of all mention of the 

 studies that have been contributed to this science on this side of 

 the Atlantic within the last few years. These studies to a large 

 extent fall in those chapters that have been most fully revised ; and 

 this, together with the fact that they have been noticed in Profes- 

 sor Ladd's ' Psychology,' makes the cause of this omission all the 

 more strange. 



Spezial Karte von Afrika. Gotha, Justus Perthes, f. 



The second edition of this valuable work on African geography 

 is now complete. It consists of ten sheets, and contains all the new 

 discoveries made during the last years. The coloring of the new 

 edition is more delicate than that of the first edition, and the politi- 

 cal boundaries have been indicated in colors that do not obscure 

 the physical features of the country. The map is carefully com- 

 piled from all the available material, and is indispensable to the 

 student of African geography. Although it is only a year since the 

 first edition was completed, the additions to our knowledge of some 

 parts of Africa are so considerable that the sheets had to be practi- 



cally redrawn. On the sheet Kongo we find the results of Capello 

 and Ivens's journey, Reichard's journeys west of the Tanganyika, 

 and the numerous explorations on the tributaries of the Kongo. 

 The contour line of 1,000 metres, which was indicated by a heavy 

 buff line in the first edition, has been corrected according to recent 

 observations, and is shown by a broken red line. Another techni- 

 cal improvement of the new edition is the use of a dark green color 

 for indicating oases. On the sheet Western Sudan we find A. 

 Krause's important journey through Mosi indicated, although the 

 details are not yet known. The leading principles in constructing 

 the map are thoroughly scientific. The lettering and the outlines 

 show plainly the parts that are known by exploration, and those 

 which are only known by reports of natives. The scale is i : 4,000,- 

 000 (about 60 miles to an inch), large enough to show all important 

 features of the geography of Africa. 



The Driftless Area of the Upper Mississippi. By T. C. Cham- 

 BERLIN and R. D. SALISBURY. (A monograph accompany- 

 ing the Sixth Annual Report of the Director of the United 

 States Geological Survey.) Washington, Government. 4°. 



In no direction is the Geological Survey advancing the science 

 more rapidly than in the department of glaciology. The monograph 

 on the great terminal moraine has done more than any other single 

 research to make the continental ice-cap a reality, and to silence 

 the iceberg theory of the drift ; and the present contribution is 

 scarcely less valuable or wide-reaching in its conclusions. 



In the midst of the great mantle of drift that overspreads the 

 Upper Mississippi basin, there lies a drift-barren tract of about ten 

 thousand square miles, — the driftless area of Wisconsin and adjoin- 

 ing States. This island in the sea of drift is unique ; and, strangely 

 enough, the margin of the drift on almost every hand lies on aslope 

 descending toward the driftless area. Probably no other district 

 on the globe is so favorably situated to serve as a standard of com- 

 parison and contrast between glaciated and unglaciated areas, and 

 a means of estimating the results of the drift agencies. All of 

 the formations of that region, with their attendant topographies, 

 sweep curvingly across the driftless area from an ice-ridden region 

 on the one hand, to a like ice-ridden region on the other, displaying 

 in a most striking manner the contrasts that arose from the single 

 factor of glaciation. The driftless region is especially instructive 

 concerning glacial extension and restriction, and it throws impor- 

 tant light upon the movements of the ice-sheet over a very large ad- 

 jacent territory. The great drift-burdened ice-stream, as it moved 

 south-westward from the Canadian heights, was divided and di- 

 verted ; and the separated currents swept around the area, and 

 mingled their burdens below it. 



The facts bearing upon these and many minor aspects of the 

 driftless area are marshalled and discussed in a masterly manner, 

 the more important features being also clearly exhibited in a series 

 of well-executed maps and cuts. Among the subordinate contrasts 

 which this region presents, none are more noticeable than the ab- 

 sence of falls in the driftless area, and their comparative abundance 

 beyond its limits, — falls indicating a youthful, and usually a post- 

 glacial, topography. And certainly there could be no more con- 

 vincing evidence that the region has never been invaded by glaciers 

 than is to be found in the fragile pinnacles of rock which abound 

 over a large part of its surface. 



The residuary' earths of the driftless area are compared physi- 

 cally, microscopically, and chemically with the glacial clay or till. 

 Nearly one million measurements of the ultimate particles show 

 that the residuary earths are much finer grained and more homo- 

 geneous than the drift clay ; and they are also remarkably free from 

 calcareous matter, which forms a large proportion of all the true 

 drift of that region. 



In its remarkably sinuous course across the continent, the great 

 terminal moraine impinges upon the eastern side of the driftless 

 area, and affords specially fine contrasts between the characteristics 

 of driftless and drift-bearing regions ; while upon the west it is 

 bordered by the loess ; and the much-disputed question as to the 

 origin of this interesting formation is settled provisionally in favor 

 of its being essentially an aqueous or lacustrine deposit of glacial 

 clays. 



In the concluding chapter, on the history and genesis of the drift- 



